1. Field of the Invention
This invention relates to a shield fixing structure that is installed at a full-face type helmet and an open face type helmet a driver wears when he or she rides on various kinds of motorized vehicles such as a motorcycle and an automobile, and more particularly, a shield fixing structure in which it may produce an outer appearance where the outer surface of the shield may become substantially flush with the outer surface of the shell when the shield is fully closed.
2. Description of the Related Art
As the shield-supporting structure in which the step segments for accepting at least the shield are formed at the shield installing positions of the shell in which it may produce an outer appearance where the outer surface of the shield may become substantially flush with the outer surface of the shell when the shield is fully closed, the structure has already been provided in the gazette of Japanese Utility Model Laid-Open No. Hei 2-22329, for example.
In this related art utility model described above, the shield is aligned with the step segment (the stage in the gazette) when the shield is fully closed to cause the outer surface of the shield (the outer side surface in the gazette) to be in flush with the outer surface of the shell (the outer side surface in the gazette).
When the shield is pushed out forwardly from this state, the front side of the shield is slid forwardly by the ratchet mechanisms installed at the right and left side surfaces of the shell and disengaged from the step segments and at the same time both right and left sides of the shield slide in the outer rightward and leftward directions and are disengaged from the step segments, resulting in that the shield can be pushed up and the shield can be fully opened.
In order to cause the shield to be fully closed again, the shield is pushed down and pushed back rearward to cause the shield to be aligned with the step segments and further the outer surface of the shield is in flush with the outer surface of the shell.
With such an arrangement as above, the related art aims to reduce wind-noise and to prevent rainwater from entering into the helmet.
As shown in FIG. 12, the ratchet mechanism in the related art is comprised of the ratchet base seat 100, the ratchet inner rotor 200, the shield holder 300, the ratchet outer rotor 400, the stopper washer 500, the bolt 600 and the ratchet cover 700, wherein each of these members is arranged to be overlapped to each other on the coaxial line at both sides of the shell 800.
As described above, since this ratchet mechanism has a substantial thickness due to the fact that many composing members are arranged to be overlapped to each other on the coaxial line at both sides of the shell 800, it is necessary that the shell is protruded inwardly by an amount corresponding to the thickness of the ratchet mechanism to make an indented notch part.
However, such an arrangement as above requires to make a thin thickness of the shock absorbing liner for absorbing shock applied to the head of the helmet wearer only in correspondence with the inward protrusion of the shell, so that it is not possible to provide a safety characteristic to the helmet wearing person.
As a method for assuring a thickness of the shock absorbing liner, it is satisfactory that the shock absorbing liner is formed in the beginning to have a thickness added with a thickness protruding inside the shell, although a size of the shell is increased in proportion to the thickness of the shock absorbing liner, resulting in that the helmet itself is made to be large in its size or its weight is increased.
That is, the utility model disclosed in the aforesaid gazette can reduce a wind-noise only after sacrifying to a certain degree a shock absorbing characteristic, an aerodynamic characteristic.
In view of the foregoing, it is an object of the present invention to provide a new shield-supporting structure in which wind-noise can be reduced.